Friday, December 19, 2014

What is cancer? Who gets cancer?

by George Johnson
I was quite curious about all this. You see, my husband has cancer. Prostate cancer. What gets me through the day is being fascinated and trying to learn all that I can.

What I learned from George Johnson's well-researched book is this...

What is cancer?

"Cancer is a phenomenon in which a cell begins dividing out of control and accumulating genetic damage."

A normal cell can only divide 50 or 60 times: this is the Hayflick phenomenon. This is why people age 55+ make up the 77% of humans with cancer diagnoses.

The nucleus of a cells gets information: they can sense mistakes, monitor and rein in growth, they can send a suicide message (apoptosis) to individual mutant cells to stop duplicating.  There is a counter that monitors how many times a cell divides. Copying itself, it can continuously learn to reset its counter and duplicate the mutations. Cells can become immortal and replicate continuously. 

Mutant cells: benign or malignant

benign tumour cannot invade neighbouring cells. It starves,  and is unable to remove waste. 

Malignant tumours learn how to invade surrounding tissues, and reaches into the circulatory system for food and the removal of waste. Once this happens, the genome can evolve, produce more adapted mutations, and get into the blood stream or lymphatic system, where it lives and reproduces even more. Malignant cells have acquired the ability to initiate angiogenesis, growing its own capillaries. Greek: karkinos = crab. This is where we get the word from, cancerous cells become crabs that reach out. Carcinogen and carcinoma. 

Who gets cancer?

  • Cancer has existed for eons in humans.
  •  A dinosaur that suffered a bone tumor 150 million years ago.
  • Sarcomas, carcinomas, lymphomas have all been found in carp and codfish.
  • Reptiles and amphibians, except for newts, are susceptible to cancer.
  • Newts tend to regrow limbs properly, after cancer.
  • Trout, like people, get cancer from a carcinogen (aflatoxin) produced by the fungus Aspergillus flavus, found in peanuts and soybeans. 
  • Mammals (7 vertebrae in their necks) appear to be more prone to developing cancer than reptiles or fish, who develop more cancer than amphibians.
  • You can have CT Scans, Bone Scans
  • Domesticated animals appear to get more cancer than wild animals. 

Cancer myths

Eating the right foods will prevent cancer. Most of these studies rely on self-reporting, which is iffy, at best. Dr. Oz need to get back to heart surgery and refrain from touting antioxidants.
If a man has smoked 3 packs a day, by age 70 he only has an 18% risk of getting lung cancer.

Known Carcinogens

Estrogen, asbestos, benzene, gamma rays and mustard gas.
Yes, Estrogen. Each month, women produce a dose of estrogen in the uterus and mammary

glands, to begin multiplying and duplicating their DNA. We know that the more cells duplicate, the more potential errors. 

Young girls are exposed to more estrogen over their lives with the lowering of the age of menarche from 16 to 12 over a 100 year period. Women are spending less time pregnant or nursing. Women are having more menstrual cycles over their lifetimes.

What do we know?

Here we are, prior to his
Robotic prostatectomy
Johnson is right: most of us misunderstand cancer.
  • Tobacco is a cause in 30% of cancer deaths; diet/lack of exercise accounts for about 35%.
  • Cancer deaths below age 65 have been decreasing since 1953 (aside from smokers).
  • For about 50 - 60% of cancer diagnoses we do not know the cause.
  • The two highest risk factors for cells to become cancerous are obesity and old age.
  • Entropy × mitosis × time = breakdown in cells =  cancerous cells
  • Robert A. Weinberg, the eminent cancer biologist who led the discovery of oncogenes (cancer-causing genes). Every second four million of the cells in our body are dividing, copying their DNA. With every division there are imperfections. 
  • The most common 3 cancers: colon, prostate and breast cancer.
  • Cancer can be spread by physician intervention; Physician: Do no harm: Health Canada warns surgery using a morcellator could spread undetected cancer
*Entropy the natural tendency for order to give way to disorder.” Mitosis is cell replication. All cells divide and divide more, copying their own DNA. Mistakes happen. Mistakes happen more often in older cells.

A group of researchers, including a Saskatchewan scientist, have found what may be the oldest case of human cancer in the world.

A group of researchers, including a Saskatchewan scientist, have found what may be the oldest case of human cancer in the world.

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